Lifting jack



March 27, 1951 R. .H. FLOYD LIFTING JACK Filed Aug. 20, 1945 INVENTOR. /Qy/ F70 a ATT/PNEY listened Mar. 27,` 1951 LIFTING JACK Rarv H.Floyd, Los'Angeles, Calif., assigner of onehalf to James O. Warner and Alfred P. Peracca, -both of Los Angeles, Calif.

Application August 20, 1945, Serial No. 611,583 1 claim. (ci. zei- 126) My invention relates to a lifting jack, and more particularly to a jack adapted primarily for lifting automotive vehicles. An important object of the invention is to provide in such a device, mechanism of exceptional strength and simplicity having a leverage arranged to exert the maximum amount of energy upon the lifting operation.

Another object is to provide easily. operable means to draw together opposed ends of crossed levers, to effect the lifting operation.

My invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected'therefrom, economical of manufacture, relatively simple, an of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. How--I ever, the drawings merely show and the following description merely describes one embodiment of the present invention, which is given by Way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

Fig. 1 is a side elevational view of a lifting jack embodying the foregoing objects.

Fig. 2 is a plan view of same.

Fig. 3 is an enlarged section taken on the line 3-3 of Fig. 2.

lReferring more in detail to the drawings, the reference number 6 generally designates a base plateV upon which my jack is mounted and upon which it operates. An end 'I of the plate 6 is turned up, to provide a stop, as hereinafter more fully described.

A block 8 is fastened upon the plate 6 by bolts 9. Rotatably supported in a bore I D in the block 8 is a shaft I2, the outer end I3 of which is threaded. A nut I4 is carried on the threaded portion I3 of the shaft.

Stub axles I and I6 are mounted in the nut I 4 to project laterally therefrom and to support wheels I'I and I8 that roll on the base plate 6. Cotter pins I9, or other suitable means, may be employed to hold the wheels Il on their respective axles.

Lazyltong, crossed levers and 2I at opposite sides ofthe jack are respectively pivoted at their lower ends to the block 3 and to the nut I4. Enlargements 22 on the block 8 support stub axles 23 upon which the lower ends of the levers 20 are pivoted. Here again cotter pins 24, or other suitable means, may be employed to maintain the levers on the axles. The axles I 5, I6 and 23, have been shown tubular, which is a satisfactory construction. The lower ends of the levers 2| are pivoted on the axles I5 and I6, between the wheels II and I8 and the nut I4.

Pins 25 pivotally connect the crossed levers 20 and 2I in an arrangement in which the lower legs of the crossed levers (connected with the axles I5, I6 and 23) are longer vthan the upper ends 26 and 2'I of the levers 20 and 2|, respectively. This arrangement facilitates the lifting operation by increasing the leverage correspondingly. f r.

A shoe plate 28 is supported on the upper ends of the lever arms 26 and 21. A heel 29 on the plate 28 is pivotally connected to the lever arm '2l by an axle 36 that extends through the heel 29 transversely to connect with both of the upper arms 2l. Cotter pins 3|, or other suitable means, prevent the escape of the arms 2'I from the axle 30. I

A roller 32, preferably at least as long as the width of the toe 33 of the shoe 28, supports the toe portion of the shoe 28. The roller 32 in turn is supported by an axle 34 which is supported on the upper ends of the lever arms 25. Cotter pins 35, or other suitable means, prevent the escape of the arms 26 from the axle 34.

The shoe plate 28 comprises a rib 36 that contains a seat 31 for engaging a portion of the vehicle or other article or device to be lifted, to prevent slippage therefrom.

The outer end of the shaft I2 carries a head 38 provided with an eye 39 for engagement with an actuating tool. Abutting the head 38, on the shaft, is a collar 40. A pin 4I fastens the collar to the shaft. A thrust bearing 42 is disposed between the collar 40 and the block 8. A collar 43 is shrunk, or otherwise suitably fastened, upon the shaft I2. The collars 48 and 43 limit longitudinal movement of the shaft I2.

The operation of my present lifting jack is as follows: While the jack is in a lowered position, it is slid under the Vehicle or other article or device to be lifted. The upturned end 'I of the base provides a stop to limit outward movement of the nut I4. When the jack is in position, the shaft I2 is turned through the intermediary of a tool (not shown) engaging the eye 39. Turning the shaft I 2 causes the nut I4 to be drawn toward the block 8, thereby effecting a lifting action upon the shoe plate 28 and its supported weight. Releasing the jack from its Weight supporting position is effected by reversing the rotation of the shaft I2 until the plate 28 is lowered out of engaging position with the vehicle or other article or device. Then the jack can be pulled out from under the vehicle, article or device.

1t is believed apparent that the top of the plate 6 provides a smooth surface upon which the Wheels I1 and I8 can roll free from obstruction, while the relative shortness of the upper ends 26 and 2] ogf the levers Jiricilesefs .the lever age andlifting power of the jack.

While I have illustrated and described whatl now regard as the preferred embodiment of my invention, the construction is, of course, subject to modifications Without departing from the spirit andscope of my invention. 1, therefore, do not wish to restrict myself to ythe particular form -rport plate parallel to the base plate :and :spaced 'I' thereabove, a longitudinal rupstanding `rib on :the support lvplate and hav-ing a. vehicleeengaging .and locating seat lforrned -in kthe end .thereof that is on the journal block-carrying end `of the base plate, a pivot-connecting block fixed to `and .deepe-ndingffrom the `under-iace of the support plate on the end :thereof beneath `the seat in `Athe rib, two :similar pairs of levers pivotally connected at a point whereby one lendet each pair is .short- -er than the other end, the .shorter rends .being equal in length and the longer .ends also being equal in length, `:the longer :ends `of one vpair Aof Vleversbeing connected to vthe axles of the fmen.- tioned ournal .'block, -ra roller connecting the :shorter ends of said latter pair .ofilevers andhav.-

ing rolling and supporting engagement with said under face of the support plate from the mentioned pivotcon.necting block toward the opposite end of said support plate, an internally threaded block having laterally extending fixed axles connecting the longer ends of the other pair of levers, rollers on said latter axles having rolling engagement With the upper face of the ibase Vplate between the `upturned Yend thereof and the journal block thereon, laterally extending pivot pins in the mentioned pivot-connecting :block for connecting the shorter ends of said @other pair of levers, said pins being spaced from the 'under face of the support plate a distance ,equal to theradius of the roller engaged with said under face `whereby the support plate is maintained parallel to the base plate during all `.pivotal positions .of the pairs of levers, and a shank rotatable in the journal block and having a threaded end engaged with the internally threaded block to move the latter in a path parallel nto .the Y:base Vplate to thereby angularly adiust vthe pairs 'of levers ,rela-tive to each ,other ,and thereby adjust the :space between the base pla-te yand support plate.

RAY H.

REFERENCES CITED The 'following references are vof vrecord in the file of this patent:

UNITED .STATES PATENTS 

